1. Field of the Invention
The present invention relates to an apparatus for testing a hard disk drive in a test process performed in the manufacture of hard disk drives, and more particularly, to a hard disk drive testing apparatus that employs only one host computer to test a plurality of hard disk drives in a burn-in (B/I) test process.
2. Description of the Related Art
As is generally known, a hard disk drive (HDD) combines and includes a head disk assembly (HDA) made up of mechanical components, and a printed circuit board assembly (PCBA) made up of circuit components. An HDD is generally used as a complementary memory device in which a head hovers a minute distance above a turning magnetic disk, data is magnetically recorded on or read from the disk, and a large volume of data can be accessed at a high speed.
HDDs are generally manufactured through a mechanical assembly process, a servo write process, a function test process, and a burn-in test process, and are then put through a post process, which is like a final test process to confirm whether an HDD set that passed the burn-in test process was normally settled with defect processing. A process of manufacturing an HDD will now be described in detail. First, the mechanical assembly process is a process of assembling an HDA from mechanical components, and is usually performed in a clean room. The servo write process, performed second, is a process of recording a servo write pattern for servo control of an actuator on a disk, and is usually performed by a servo writer. The function test process, performed third, combines the HDA produced in the mechanical assembly process with the PCBA, and tests whether they match properly and operate together normally. In the function test process, the combination of the HDA and the PCBA is combined with a specific test system and put through a basic test for about 20 to 25 minutes. The burn-in test process, performed fourth, is the process that takes the longest time (usually 8 through 16 hours) in the manufacture of an HDD. In the burn-in test process, any defects on the disk are found and corrected.
The final post test process, performed fifth, is a process to confirm whether an HDD set which passed the above-described burn-in test process was normally settled with defect processing, and tests the defect processing status of every HDD set using the specific test system. The final test process connects each HDD to a separate test computer and performs tests. Each test computer is connected to a host computer over a local area network (LAN), tests a connected HDD according to a test program, and outputs the results to the host computer. The host computer displays status data input from each test computer on a display unit, and workers decide success or failure while monitoring the status data. HDDs that pass the final test process are shipped as finished products through a shipment test process, a packing and shipping process, etc.
Since, as described above, the burn-in test process takes the longest time in manufacturing an HDD, a burn-in testing apparatus is needed which can reliably test as many HDDs as possible in a limited time and in a limited space. Conventional testing apparatuses are disclosed in Korean Patent Publication No. 1997-76738 (Dec. 12, 1997), Korean Patent Publication No. 1998-35445 (Aug. 5, 1998), Korean Patent Publication No. 1999-60619 (Jul. 26, 1999), Korean Patent Publication No. 1999-65516 (Aug. 5, 1999), U.S. Pat. No. 6,434,498 (Aug. 13, 2002), U.S. Pat. No. 6,208,477 (Mar. 27, 2001) and U.S. Pat. No. 6,434,499 (Aug. 13, 2002).
FIG. 1 shows the exterior of a conventional hard disk drive testing apparatus disclosed in Korean Patent Publication 1997-76738, filed by Samsung Electronics Co., Ltd., assignee of the present application. Referring to FIG. 1, a burn-in chamber 30 where HDDs are stacked is located in the front, and a control chamber 40, which is made up of lined-up power cards, is located in the rear of the HDD testing apparatus 200 and separated from the control chamber 30 by a partition 80. The power cards control the supply of power to each HDD stacked in the burn-in chamber 30, and to 20 to 24 test computers 50. Typically, each test computer 50 controls and monitors (tests) 6 HDDs.
A power distribution unit installed at an end of the control chamber 40 distributes power to the power cards and a host computer which manages the test computers 50 and receives input/output instructions from a manager. Meanwhile, a DC power supply installed at the other end of the control chamber 40 supplies power to the HDDs to be tested. Also, a display unit and a keyboard (not shown) are attached at one end of the burn-in chamber 30 for user interface, and heaters & blowers are installed at both ends of the burn-in chamber for keeping a high temperature in the burn-in chamber 30.
FIG. 2 is a block diagram which shows the internal configuration of the apparatus shown in FIG. 1. Referring to FIG. 2, for the HDD test apparatus 200 shown in FIG. 1, one host computer 600 and 20 to 24 test computers 612–618 are connected through a first control bus 660, and three dual channel IDE adapters 622, 624, and 626 are also connected to each test computer 612–618 through a second control bus 630. Also, two HDDs (pairs of 642–644, 646–648, and 650–652) are connected to each dual channel IDE adapter 622, 624, and 626, respectively.
After booting the host computer 600, the host computer 600 sets up a communication network with the test computers 612–618 through the first control bus 660, which may be embodied as a typical LAN or as some other type of connection. The test computers 612–618 are booted through the first control bus 660 to execute the test program and form a communication channel between the test computers 612–618 and the host computer 600. When the communication channel between the test computers 612–618 and the host computer 600 is formed, the host computer 600 receives status information from each test computer 612–618, displays the status on the screen of the display unit, and controls the temperature inside the burn-in chamber 30 using the heaters and blowers.
When HDDs to be tested are inserted into the burn-in chamber 30 of the HDD testing apparatus 200, the test computers 612–618 detect the HDD, for example, the HDD 652, insertion and upload a test code and script to the HDD 652 via the dual channel IDE adapter 626. After this, the test computers 612–618 monitor the test results or the progress status through the IDE interface and transfer the data to the host computer 600, which then displays the test results or progress status on the screen of the display unit.
The conventional testing apparatus 200 shown in FIGS. 1 and 2 has a structure which connects each test computer to 6 HDDs, and thus is more efficient than prior 1 to 1 test methods. However, the testing apparatus 200 shown in FIGS. 1 and 2 still requires 20 to 24 test computers. These test computers require a control chamber 40 of considerable size to house them. Also, because 3 expensive dual IDE adapters per test computer need to be installed, the testing apparatus 200 shown in FIGS. 1 and 2 is not significantly cheaper to build and implement than prior 1 to 1 test apparatuses. Also, there is a significant possibility of error generation, because, as shown in FIG. 2, the host computer 600 is connected to the test computers 612–618 through a three tier complex communication structure (i.e., the typical communication structure connecting one computer to another computer), and each of the test computers 612–618 again control the HDDs via another communication structure, which is the dual IDE adapters. Accordingly, because of the complex communication structure, it is also difficult to debug the system when an error occurs. Moreover, if the interface standard of the HDDs is changed, all IDE adapters must be replaced and the test program loaded in the test computers 612–618 must be modified.